The present invention relates generally to signal lights and, more particularly, to an improved construction for a rotating signal or warning light of the type used on police and fire department vehicles, emergency road vehicles, ambulances, and the like.
U.S. Pat. No. 3,117,302 to Cardarelli discloses a rotating signal light in which a metallic lamp holder is fixedly attached to a vertical shaft. The shaft carries a worm gear which is driven by a worm fixed to the shaft of a motor mounted in the base of the light. Electrical connections are made by the terminals of the lamps mounted on the lamp holder by either wires, or metallic plates, which are connected to the terminals by screws. The wires may also be electrically connected to the terminals by soldering. One of the conductors to the terminals of the lamps is connected to the drive shaft for the lamp holder which is in turn connected to ground. The other conductor must be separated from the shaft and the metallic lamp holder by means of separate insulators. Reference is also made to U.S. Pat. No. 3,271,735 to Gosswiller which discloses a similar type of rotatable signal light which utilizes a metallic lamp holder. The prior art rotatable lights require a large number of parts, thereby increasing the manufacturing costs of the lights and the cost of maintaining an inventory of parts. Further, in the prior art constructions a slip ring is fixedly mounted below the rotating lamp holder and a brush is mounted on the holder for slidably engaging the slip ring. As a result, if contaminants fall on the top of the slip ring, the electrical connection between the ring and the brush may be adversely affected.
The purpose of the present invention is to provide a rotatable signal light which is simpler in design, utilizes a fewer number of parts, and therefore less expensive to produce and assemble than the aforementioned prior art signal lights. Further, it is an object of the invention to overcome the problem of contaminants falling on the slip ring. In addition, another purpose of the invention is to provide a signal light which is readily adaptable by the use of identical components to mount four lamps rather than two.